The present invention relates generally to improvements in cameras and it relates more particularly to an improved compact single lens reflex camera of the film cassette type and provided with a zoom lens objective lens system.
Compact cameras employing a 16mm cassette film or other similar narrow film are currently widely used and are known as handy pocket type cameras. With such cameras of conventional construction, the image formed in the narrow or short film frame can be properly enlarged only within relatively narrow limits. To obtain a highly enlarged clear picture of satisfactory resolution of a subject, it is advisable to photograph the subject as large as possible. However, restricted by the photographing conditions such as location and other parameters, the angle view cannot always be very freely selected. For the purpose of obtaining wide angles of view, some of the currently used cameras of the subject type are equipped with a close-up adapter lens which, however, does not work very effectively under ordinary photographing operations. It is known in cameras employing a film with a small frame size that several remarkable and highly desirable effects can be obtained by the use of a zoom lens that provides an adjustable angle of view. Such a zoom lens, however, is highly unsuitable to fully achieve the desired effects and results unless the camera is so designed that the adjusted angle of view is readily recognized or observed by the photographer. However, with the view finders commonly employed in conventional compact cameras of the subject type any adjustment of the angle of view with satisfactory parallax correction is not generally realized.
It is accordingly clear that the conventional cassette type compact single lens reflex camera possesses numerous drawbacks and disadvantages which are not remedied by the use of a zoom lens of common design.